High-frequency filter including matching circuit

ABSTRACT

A high-frequency filter includes a first output to output a first signal, a first filter, a second filter, and a first matching circuit connected to an output of the first filter and to an output of the second filter. The first signal is provided to the first output from one of the output of the first filter and the output of the second filter via the first matching circuit. The first matching circuit includes a resonator connected in series between the first output and the output of only one of the first filter and the second filter.

RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 120 as a continuationof U.S. patent application Ser. No. 14/241,877, titled “HIGH-FREQUENCYFILTER,” filed on Feb. 27, 2014, which is herein incorporated byreference in its entirety. U.S. patent application Ser. No. 14/241,877is a national stage entry under 35 U.S.C. § 371 of PCT ApplicationSerial No. PCT/JP2012/006808, titled “HIGH-FREQUENCY FILTER,” filed onOct. 24, 2012. PCT Application Serial No. PCT/JP2012/006808 claimspriority to Japanese Patent Application No. 2011-259362, filed on Nov.28, 2011.

TECHNICAL FIELD

The present invention relates to a high-frequency filter.

BACKGROUND ART

The number of duplexers mounted on a mobile phone has been increasingassociated with the mobile phone's ability to handle multiple bands andmultiple modes. On the other hand, in order to solve the shortage ofspace caused by acceleration in adding multiple functions to the mobilephone, the request for reducing size of a wireless section has becomestrong. Because of such background, expectation is high for amulti-duplexer module having integrated therein multiple duplexers.

Patent Literature 1 discloses a multi-duplexer module 1000 shown in FIG.12. The multi-duplexer module 1000 includes an antenna terminal 1002, amatching circuit 1031, a first duplexer 1032, and a second duplexer1033. The first duplexer 1032 and the antenna terminal 1002 areconnected via the matching circuit 1031.

CITATION LIST Patent Literature

[PTL 1] Japanese Laid-Open Patent Publication No, 2010-45563

[PTL 2] Japanese Laid-Open Patent Publication No. 2000-315936

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

FIG. 13 shows an example of connection between the multi-duplexermodule, and an antenna and a transceiver. In the example shown in (a) ofFIG. 13, transmission side terminals and reception side terminals of thefirst duplexer 1032 and the second duplexer 1033 are each connected to aterminal of the transceiver via PAs (amplifiers) 1101 to 1104 throughwiring. Furthermore, as in the example shown in (b) of FIG. 13, it hasbeen considered assigning multiple functions to a PA. In this example,each of the transmission side terminals of the first duplexer 1032 andthe second duplexer 1033 is connected to a terminal of the transceivervia a switch 1301. When passbands of each transmission side filter ofthe first duplexer 1032 and the second duplexer 1033 overlap or areadjacent to each other, multiple functions can be assigned to the PA1102 by including the switch 1301.

However, when a plurality of transmission-and-reception filters such asduplexers are arranged, various problems occur such as wiring becomingcomplicated, power consumption increasing due to insertion loss by anewly added switch, distortion being generated by the switch, andneeding an additional circuit and wiring for switch control.

Thus, an objective of the present invention is to provide ahigh-frequency filter that is capable of handling multiple bands andthat allows assigning multiple functions to a PA and simplifying wiringand circuits without using a switch.

Solution to the Problems

The present invention is a high-frequency filter including a firstfilter, a second filter, and a first matching circuit connected to aninput side of the first filter and an input side of the second filter.Furthermore, a first input, which is an input to the high-frequencyfilter, is inputted to the first filter or the second filter via thefirst matching circuit.

Furthermore, the first matching circuit includes at least one firstresonator, and the at least one resonator is connected in series to aninput side of, among the first filter and the second filter, a filterwhose passband is a higher frequency band.

The high-frequency filter further includes a first reception filter anda second reception filter. Furthermore, the first input is atransmission signal, the first filter and the second filter arerespectively a first transmission filter and a second transmissionfilter to both of which the transmission signal is inputted, and areception signal, which is a second input inputted to the high-frequencyfilter, is inputted to the first reception filter and the secondreception filter.

Furthermore, the high-frequency filter further includes a secondmatching circuit connected to an output side of the first receptionfilter and an output side of the second reception filter.

Furthermore, the second matching circuit includes at least one secondresonator, and the at least one second resonator is connected in seriesto an input side of, among the first reception filter and the secondreception filter, a filter whose passband is a higher frequency band.

Furthermore, at least one set, selected from a set including the firsttransmission filter and the first reception filter and a set includingthe second transmission filter and the second reception filter, isformed as a duplexer.

Furthermore, a frequency band of a passband of the second transmissionfilter is higher than a frequency band of a passband of the firsttransmission filter, a frequency band of a passband of the secondreception filter is higher than a frequency band of a passband of thefirst reception filter, and the frequency band of the passband of thesecond transmission filter and the frequency band of the passband of thefirst reception filter partially overlap.

Furthermore, at least one among the first transmission filter, thesecond transmission filter, the first reception filter, and the secondreception filter is formed from an elastic wave filter that utilizesnon-leakage elastic waves.

Furthermore, the high-frequency filter further may include an amplifier,wherein the first input may be amplified by the amplifier, and may beinputted to the first filter or the second filter via the first matchingcircuit.

Furthermore, the high-frequency filter may further include an antennaswitch connected to output sides of each of the transmission filters andinput sides of each of the reception filters.

Advantageous Effects of the Invention

With the high-frequency filter of the present invention, it is possibleto assign multiple functions to a PA and simplify wiring and circuits,without using a switch.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the configuration and connection mode of a high-frequencyfilter according to a first embodiment of the present invention.

FIG. 2 shows the configuration and connection mode of the high-frequencyfilter according to a second embodiment of the present invention.

FIG. 3 shows the configuration and connection mode of the high-frequencyfilter according to a third embodiment of the present invention.

FIG. 4 shows the configuration and connection mode of the high-frequencyfilter according to a fourth embodiment of the present invention.

FIG. 5 shows the configuration and connection mode of the high-frequencyfilter according to a fifth embodiment of the present invention.

FIG. 6 shows the configuration and connection mode of the high-frequencyfilter according to a sixth embodiment of the present invention.

FIG. 7 shows the configuration and connection mode of the high-frequencyfilter according to a seventh embodiment of the present invention.

FIG. 8 shows characteristics of the high-frequency filter according to afirst Example of the present invention.

FIG. 9 shows characteristics of the high-frequency filter according tothe first Example of the present invention.

FIG. 10 shows characteristics of the high-frequency filter according tothe first Example of the present invention.

FIG. 11 shows the configuration and connection mode of thehigh-frequency filter according to a second Example of the presentinvention.

FIG. 12 shows the configuration of a hitherto known multi-duplexermodule.

FIG. 13 shows connection modes of the hitherto known multi-duplexermodule.

DESCRIPTION OF EMBODIMENTS First Embodiment

In the following, a first embodiment of the present invention will bedescribed. FIG. 1 shows the configuration of a high-frequency filter 100according to the present embodiment, and one example of its connectionwith an antenna, a transceiver, etc. The high-frequency filter 100includes a substrate 101 and components disposed on the substrate, suchas a first transmission filter 111, a second transmission filter 112, afirst matching circuit 121, an input terminal 131 to which transmissionsignals outputted from a transceiver 901 and amplified by a PA 904 areinputted, a first antenna terminal 141, and a second antenna terminal142. Transmission signals are inputted to the input terminal 131. Theinput terminal 131 is connected to the first transmission filter 111 andthe second transmission filter 112 via the first matching circuit 121.Outputs of the first transmission filter 111 and the second transmissionfilter 112 are respectively connected to the first antenna terminal 141and the second antenna terminal 142. The first antenna terminal 141 andthe second antenna terminal 142 are connected to an antenna 903 via anantenna switch 902.

The first transmission filter 111 and the second transmission filter 112may be formed from, for example, elastic wave filters such as DMSfilters and rudder type filters utilizing non-leakage waves.

The first matching circuit 121 performs matching between the firsttransmission filter 111 and the second transmission filter 112. Thefirst matching circuit 121 can be achieved by grounding and connectingan inductor 152 parallel with respect to a signal route, and connecting,in series, a first resonator 153 to an input side of at least one of thefirst transmission filter 111 and the second transmission filter 112.The first resonator 153 is preferably connected in series to an inputside of, among the first transmission filter 111 and the secondtransmission filter 112, the one whose passband is a higher frequencyband. The first resonator 153 has characteristics of a capacitor, andfunctions as a high pass filter when connected in series. Therefore,when the first resonator 153 is connected in series to an input side ofa transmission filter whose passband is a higher frequency band, it ispossible to suppress transmission signals corresponding to a lowfrequency band from being inputted to the transmission filter. In thepresent embodiment, the frequency band of the passband of the secondtransmission filter 112 is set to be higher than the frequency band ofthe passband of the first transmission filter 111, and the firstresonator 153 is connected in series to the input side of the secondtransmission filter 112. It should be noted that a resonator may beconnected in series to each of both the input side of the firsttransmission filter 111 and the input side of the second transmissionfilter 112. Furthermore, the first matching circuit 121 may be formedusing other circuit configurations.

Furthermore, as shown in FIG. 1, matching circuits 122 and 123 may befurther disposed respectively between the first transmission filter 111and the first antenna terminal 141, and between the second transmissionfilter 112 and the second antenna terminal 142.

When the first matching circuit 121 is disposed on each of the inputsides of the first transmission filter 111 and the second transmissionfilter 112, passband characteristics of each of the first transmissionfilter 111 and the second transmission filter 112 are exerted even iftransmission signals are inputted through the same wiring, and therebythe PA 904 and the wiring between a transmission signal output terminalof the transceiver 901 and the input terminal 131 of the high-frequencyfilter 100 can be assigned with multiple functions. With this, itbecomes unnecessary to provide a switch for switching an inputdestination of transmission signals or a circuit for controlling thisswitching, and thereby wiring and circuits can be simplified.

Second Embodiment

In the following, a second embodiment of the present invention will bedescribed. FIG. 2 shows the configuration of a high-frequency filter 200according to the present embodiment, and one example of its connectionwith an antenna, a transceiver, etc. The high-frequency filter 200 isobtained by further including, to the high-frequency filter 100according to the first embodiment, a first output terminal 261, a secondoutput terminal 262, a first reception filter 211, and a secondreception filter 212.

Reception signals from the antenna 903 are branched at the antennaswitch 902 and inputted to the first antenna terminal 141 and the secondantenna terminal 142. Reception signals inputted to the first antennaterminal 141 are inputted to the first reception filter 211, andreception signals inputted to the second antenna terminal 142 areinputted to the second reception filter 212. Furthermore, an output ofthe first reception filter 211 is connected to the first output terminal261, and an output of the second reception filter 212 is connected tothe second output terminal 262. The first output terminal 261 and thesecond output terminal 262 are connected to a transceiver 911, and a PA905 and a PA 906, built in the transceiver 911, amplify receptionsignals.

The first reception filter 211 and the second reception filter 212 maybe formed from, for example, elastic wave filters such as DMS filtersand rudder type filters utilizing non-leakage waves.

Also in the present embodiment, the PA 904 and the wiring between atransmission signal output terminal of the transceiver 911 and the inputterminal 131 of the high-frequency filter 200 are assigned with multiplefunctions. With this, similarly to the first embodiment, it becomesunnecessary to provide a switch for switching an input destination oftransmission signals or a circuit for controlling this switching, andthereby wiring and circuits can be simplified.

Third Embodiment

In the following, a third embodiment of the present invention will bedescribed. FIG. 3 shows the configuration of a high-frequency filter 300according to the present embodiment, and one example of its connectionwith an antenna, a transceiver, etc. The high-frequency filter 300 isobtained by further including, to the high-frequency filter 200according to the second embodiment, a second matching circuit 322connected to the output side of the first reception filter 211 and theoutput side of the second reception filter 212, and by including,instead of the first output terminal 261 and the second output terminal262, a third output terminal 363 to which each of the outputs of thefirst reception filter 211 and the second reception filter 212 areconnected via the second matching circuit 322.

The second matching circuit 322 performs matching between the firstreception filter 211 and the second reception filter 212. The secondmatching circuit 322 can be achieved by grounding and connecting aninductor 352 parallel with respect to a signal route, and connecting, inseries, a second resonator 353 to an output side of at least one of thefirst reception filter 211 and the second reception filter 212. Thesecond resonator 353 is preferably connected in series to an output sideof, among the first reception filter 211 and the second reception filter212, a reception filter whose passband is a higher frequency band. Withthis, reception signals corresponding to a low frequency band can beremoved from the output of the reception filter. In the presentembodiment, the frequency band of the passband of the second receptionfilter 212 is set to be higher than the frequency band of the passbandof the first reception filter 211, and the second resonator 353 isconnected in series to the output side of the second reception filter212. It should be noted that a resonator may be connected in series toeach of both the output side of the first reception filter 211 and theoutput side of the second reception filter 212. Furthermore, the secondmatching circuit 322 may be formed using other circuit configurations.

Also in the present embodiment, the PA 904 and the wiring between atransmission signal output terminal of a transceiver 921 and the inputterminal 131 of the high-frequency filter 300 are assigned with multiplefunctions. Furthermore, the third output terminal 263 is connected tothe transceiver 921, and a PA 907 built in the transceiver 921 amplifiesreception signals. Thus, the PA 907 and the wiring between a receptionsignal input terminal of the transceiver 921 and the third outputterminal 363 of the high-frequency filter 300 are assigned with multiplefunctions. With this, the wiring can be further simplified.

Fourth Embodiment

In the following, a fourth embodiment of the present invention will bedescribed. FIG. 4 shows the configuration of a high-frequency filter 400according to the present embodiment, and one example of its connectionwith an antenna, a transceiver, etc. The high-frequency filter 400 isobtained by including, to the high-frequency filter 200 according to thesecond embodiment, a filter 413 and a filter 414 each having anunbalanced-balanced conversion function as the first reception filter211 and the second reception filter 212, and by including fourth toseventh output terminals 464, 465, 466, and 467 instead of the firstoutput terminal 261 and the second output terminal 262. Two outputsignal lines of the first reception filter 413 are respectivelyconnected to the fourth output terminal 464 and the fifth outputterminal 465, and two output signal lines of the second reception filter414 are respectively connected to the sixth output terminal 466 and theseventh output terminal 467.

The first reception filter 413 and the second reception filter 414 maybe formed from, for example, elastic wave filters such as DMS filtersand rudder type filters utilizing non-leakage waves.

Also in the present embodiment, the PA 904 and the wiring between atransmission signal output terminal of a transceiver 931 and the inputterminal 131 of the high-frequency filter 200 are assigned with multiplefunctions. With this, similarly to the first embodiment, it becomesunnecessary to provide a switch for switching an input destination oftransmission signals or a circuit for controlling this switching, andthereby wiring and circuits can be simplified.

Fifth Embodiment

In the following, a fifth embodiment of the present invention will bedescribed. FIG. 5 is a configurational drawing of a high-frequencyfilter 500 according to the present embodiment. The high-frequencyfilter 500 is obtained by including, to the high-frequency filter 300according to the third embodiment, the first reception filter 413 andthe second reception filter 414 each having an unbalanced-balancedconversion function as the first reception filter 211 and the secondreception filter 212 similarly to the fourth embodiment, by including aneighth output terminal 568 and a ninth output terminal 569 instead ofthe third output terminal 363, and by including a third matching circuit523 instead of the second matching circuit 322. Two output signal linesof the first reception filter 413 are respectively connected to theeighth output terminal 568 and the ninth output terminal 569, and twooutput signal lines of the second reception filter 414 are alsorespectively connected to the eighth output terminal 568 and the ninthoutput terminal 569.

The third matching circuit 523 performs matching between the firstreception filter 413 and the second reception filter 414. The thirdmatching circuit 523 can be attained by connecting an inductor 552between the eighth output terminal 568 and the ninth output terminal569, and by serially connecting a third resonator 553 and a fourthresonator 554 to the output signal lines on the output side of, amongthe first reception filter 413 and the second reception filter 414, theone whose passband is a higher frequency band. By serially connecting aresonator to the output side of a reception filter whose passband is ahigher frequency band, reception signals corresponding to a lowfrequency band can be removed from the output of the reception filter.In the present embodiment, the frequency band of the passband of thesecond reception filter 414 is set to be higher than the frequency bandof the passband of the first reception filter 413, and the thirdresonator 553 and the fourth resonator 554 are connected in series tothe output side of the second reception filter 414. It should be notedthat a resonator may be connected in series to each of both the outputside of the first reception filter 211 and the output side of the secondreception filter 212. Furthermore, the third matching circuit 523 may beformed using other circuit configurations.

Also in the present embodiment, the PA 904 and the wiring between atransmission signal output terminal of a transceiver 941 and the inputterminal 131 of the high-frequency filter 500 are assigned with multiplefunctions. A PA 909 and the wiring between a reception signal inputterminal of the transceiver 941, and the eighth output terminal 568 andthe ninth output terminal 569 of the high-frequency filter 500 areassigned with multiple functions. With this, the wiring can be furthersimplified.

Sixth Embodiment

In the following, a sixth embodiment of the present invention will bedescribed. FIG. 6 is a configurational drawing of a high-frequencyfilter 600 according to the present embodiment. The high-frequencyfilter 600 is obtained by, in the high-frequency filter 400 according tothe fourth embodiment, forming the first transmission filter 111 and thefirst reception filter 413 with a first duplexer 611, and forming thesecond transmission filter 112 and the second reception filter 414 witha second duplexer 612. The connection mode of the high-frequency filter600 with respect to an antenna and a transceiver is similar to that ofthe high-frequency filter 400 according to the fourth embodiment shownin FIG. 4. Therefore, it becomes unnecessary to provide a switch forswitching an input destination of transmission signals or a circuit forcontrolling this switching, and thereby wiring and circuits can besimplified.

It should be noted that, in the high-frequency filter 600, although aset including the first transmission filter 111 and the first receptionfilter 413 and a set including the second transmission filter 112 andthe second reception filter 414 are both formed with a duplexer, it ispossible to form only either one of those with a duplexer.

Seventh Embodiment

In the following, a seventh embodiment of the present invention will bedescribed. FIG. 7 is a configurational drawing of a high-frequencyfilter 700 according to the present embodiment. The high-frequencyfilter 700 is obtained by, in the high-frequency filter 500 according tothe fifth embodiment, forming the first transmission filter 111 and thefirst reception filter 413 with a first duplexer 711, and by forming thesecond transmission filter 112 and the second reception filter 414 witha second duplexer 712. The connection mode of the high-frequency filter700 with respect to an antenna and a transceiver is similar to that ofthe high-frequency filter 500 according to the fifth embodiment shown inFIG. 5. Furthermore, the PA 904 and the wiring between a transmissionsignal output terminal of the transceiver and the input terminal 131 ofthe high-frequency filter 500 are assigned with multiple functions. Inaddition, the PA 909 and the wiring between a reception signal inputterminal of the transceiver 941, and the eighth output terminal 568 andthe ninth output terminal 569 of the high-frequency filter 500 areassigned with multiple functions. With this, the wiring can be furthersimplified.

It should be noted that, in the high-frequency filter 700, although aset including the first transmission filter 111 and the first receptionfilter 413 and a set including the second transmission filter 112 andthe second reception filter 414 are both formed with a duplexer, it ispossible to form only either one of those with a duplexer.

As another embodiment, in the high-frequency filters 200 and 300according to the second and third embodiments, it is possible to form atleast one set, among a set including the first transmission filter 111and the first reception filter 211, and a set including the secondtransmission filter 112 and the second reception filter 212, with aduplexer.

Example 1

A first Example of the present invention will be described. Ahigh-frequency filter 800 according to the present Example is obtainedby, in the high-frequency filter 500 according to the fifth embodiment,forming the first transmission filter 111 and the first reception filter413 so as to respectively support frequency bandwidth of transmissionand reception in band 5 (transmission: 824 to 849 MHz, reception: 869 to894 MHz), and forming the second transmission filter 112 and the secondreception filter 414 so as to respectively support frequency bandwidthof transmission and reception in band 8 (transmission: 880 to 915 MHz,reception: 925 to 960 MHz).

Thus, the frequency band of the passband of the second transmissionfilter 112 is higher than the frequency band of the passband of thefirst transmission filter 111, the frequency band of the passband of thesecond reception filter 414 is higher than the frequency band of thepassband of the first reception filter 413, and the frequency band ofthe passband of the second transmission filter 112 and the frequencyband of the passband of the first reception filter 413 partiallyoverlap.

FIG. 8 is a graph showing pass characteristic between the antenna andthe input terminal 131 when the antenna switch 902 shown in FIG. 5 isswitched to the first antenna terminal 141 side and when the antennaswitch 902 is switched to the second antenna terminal 142 side. It canbe understood therefrom that passbands corresponding to the frequencybandwidth of transmission signals of band 5 and band 8 are eachachieved.

FIG. 9 is a graph showing pass characteristic between the antenna andthe eighth output terminal 568 (the ninth output terminal 569) when theantenna switch 902 shown in FIG. 5 is switched to the first antennaterminal 141 side and when the antenna switch 902 is switched to thesecond antenna terminal 142 side. It can be understood therefrom thatpassbands corresponding to the frequency bandwidth of reception signalsof band 5 and band 8 are each achieved.

FIG. 10 is a graph showing pass characteristic between the inputterminal 131 and the eighth output terminal 568 (the ninth outputterminal 569) when the antenna switch 902 shown in FIG. 5 is switched tothe first antenna terminal 141 side and when the antenna switch 902 isswitched to the second antenna terminal 142 side. It can be understoodtherefrom that isolation is ensured in frequency bandwidth oftransmission-and-reception signals in both band 5 and band 8.

Example 2

A second Example of the present invention will be described. FIG. 11shows a configuration of the present Example. The present Example isformed using high-frequency filters 100 a and 100 b, and is used forcommunication utilizing the TDD (Time Division Duplex) method ofalternately conducting transmission and reception in a time divisionalmanner. As the high-frequency filter 100 a, the high-frequency filter100 according to the first embodiment is used. The high-frequency filter100 b is obtained by including, to the high-frequency filter 100, afirst reception filter 125 and a second reception filter 126 instead ofthe first transmission filter 111 and the second transmission filter112, and by including an output terminal 132 instead of the inputterminal 131; and thereby the high-frequency filter 100 b functions as afilter for reception. Other components are similar to those in thehigh-frequency filter 100, and are referred to with reference characterscontaining identical numbers. In one example, the first transmissionfilter 111 and the second transmission filter 112 of the high-frequencyfilter 100 a respectively support frequency bandwidth for transmissionin band 5 and transmission in band 8, and the first reception filter 125and the second reception filter 126 of the high-frequency filter 100 brespectively support frequency bandwidth for reception in band 5 andreception in band 8.

To the input terminal 131 of the high-frequency filter 100 a,transmission signals outputted from the transceiver 901 and amplified bythe PA 904 are inputted. The first antenna terminal 141 and the secondantenna terminal 142 are connected to the antenna 903 via an antennaswitch 912.

A first antenna terminal 141 b and a second antenna terminal 142 b ofthe high-frequency filter 100 b are connected to the antenna 903 via theantenna switch 912, and reception signals are inputted thereto. Outputsignals from the output terminal 132 are amplified by a PA 910 andinputted to a transceiver 951.

The antenna switch 912 switches the connection destination of theantenna 903 to any one of the first antenna terminal 141 and the secondantenna terminal 142 of the high-frequency filter 100 a, and the firstantenna terminal 141 b and the second antenna terminal 142 b of thehigh-frequency filter 100 b. With this, switching can be conducted amongtransmission in band 5, transmission in band 8, reception in band 5, andreception in band 8. Communication using two bands with the TDD methodcan be attained by repeating such switching in predetermined timeslices.

Although each of the embodiments and Examples of the high-frequencyfilter of the present invention has been described above, the presentinvention can be achieved not only with the high-frequency filter byitself, but also can be achieved as a part of other electronic circuitmodules when combined with other filters etc. Furthermore, the abovedescribed antenna switches, PAs for transmission signal, etc., may beconstituent elements of the high-frequency filter. Still further,although the high-frequency filter has been described above as to beapplied to wireless transceivers, the high-frequency filter may be usedas a filter for other use application.

INDUSTRIAL APPLICABILITY

The present invention is useful as a high-frequency filter used inmobile phones etc., and is particularly useful as a high-frequencyfilter capable of handling multiple bands.

DESCRIPTION OF THE REFERENCE CHARACTERS

-   -   100, 100 a, 200, 300, 400, 500, 600, 700, 800 high-frequency        filter    -   111, 112, 125, 126 transmission filter    -   121, 121 b, 122, 123, 322, 523 matching circuit    -   131 input terminal    -   141, 141 b, 142, 142 b antenna terminal    -   152, 152 b, 352 inductor    -   153, 153 b, 353, 553, 554 resonator    -   211, 212, 413, 414 reception filter    -   132, 261, 262, 263, 363, 464, 465, 466, 467, 568, 569 output        terminal    -   611, 612 duplexer    -   901, 911, 921, 931, 941, 951 transceiver    -   902, 912 antenna switch    -   903 antenna    -   904, 905, 906, 907, 908, 909, 910 PA    -   1000 multiplexer module    -   1002 antenna terminal    -   1031 matching circuit    -   1032 first duplexer    -   1033 second duplexer    -   1301 switch

The invention claimed is:
 1. A high-frequency filter comprising: a firstinput to receive a first signal; a first filter; a second filter; afirst matching circuit connected to an input of the first filter and toan input of the second filter, the first signal being provided to one ofthe input of the first filter and the input of the second filter via thefirst matching circuit, the first matching circuit including a firstresonator connected in series between the first input and the input ofonly one of the first filter and the second filter; a second input toreceive a second signal; a first reception filter; and a secondreception filter, the first filter being a first transmission filter,and the second filter being a second transmission filter, the firstsignal being a transmission signal, and the second signal being areception signal that is provided to the first reception filter and tothe second reception filter.
 2. The high-frequency filter of claim 1wherein a frequency band of a passband of the second transmission filteris higher than a frequency band of a passband of the first transmissionfilter, a frequency band of a passband of the second reception filter ishigher than a frequency band of a passband of the first receptionfilter, and the frequency band of the passband of the secondtransmission filter and the frequency band of the passband of the firstreception filter partially overlap.
 3. The high-frequency filter ofclaim 1 further comprising a second matching circuit connected to anoutput of the first reception filter and to an output of the secondreception filter.
 4. The high-frequency filter of claim 3 wherein thesecond matching circuit includes a second resonator connected in seriesto the output of one of the first reception filter and the secondreception filter, the one of the first reception filter and the secondreception filter to which the second resonator is connected having apassband having a higher frequency than a frequency of a passband of theother of the first reception filter and the second reception filter. 5.A high-frequency filter comprising: a first output to output a firstsignal; a first filter and a second filter, the first filter being afirst reception filter and the second filter being a second receptionfilter; an antenna switch connected to an input of the first receptionfilter and to an input of the second reception filter; and a firstmatching circuit connected to an output of the first filter and to anoutput of the second filter, the first signal being provided to thefirst output from one of the output of the first filter and the outputof the second filter via the first matching circuit, the first matchingcircuit including a resonator connected in series between the firstoutput and the output of only one of the first filter and the secondfilter.
 6. The high-frequency filter of claim 5 further comprising asecond matching circuit electrically connected between an input of thehigh-frequency filter and inputs of both the first reception filter andthe second reception filter.
 7. A high-frequency filter comprising: aninput to receive a reception signal; an antenna switchably connected tothe input; a first reception filter having an input and an output, theinput of the first reception filter being coupled to the input of thehigh-frequency filter; a second reception filter having an input and anoutput, the input of the second reception filter being coupled to theinput of the high-frequency filter; and a first matching circuitconnected to the output of the first reception filter and to the outputof the second reception filter.